The second Exploratory Round Table Conference or ERTC, on the topic of “Quantum Information Science”, took place in Shanghai from 2 to 4 November 2011 under the auspices of the Shanghai Institute for Advanced Studies. The event is the second of a new series of annual conferences which are intended to provide a joint platform for scientists of both Max Planck Society (MPG) and Chinese Academy of Sciences (CAS) together with international leading scientists to discuss and evaluate newly emerging and rapidly evolving fields of research. The two supporting organisations thus create visions and seeds towards the establishments of topical areas at the leading edge of science. As such, the ERTC adds a novel instrument to ongoing processes of priority-setting in the further development of the research portfolio of both organisations.

Over the past several decades the foundations of modern information technology have been changing rapidly. The strong influx of ideas from quantum physics has led to high performance quantum algorithms, emerging new capabilities for information transmission, and a nascent generation of quantum information processing devices. This way the science of quantum information has come to light.

The field of research addresses the question of whether we can gain new functionality and power by harnessing quantum mechanical effects through storing, processing and transmitting information that is encoded in inherently quantum mechanical systems. Among the most spectacular discoveries and conjectures are quantum cryptography, which can allow the secure communication of information through public channels, and quantum computing, which may be able to efficiently solve certain computational problems believed to be intractable by classical computing. Quantum computers also allow the efficient simulation of complex quantum systems themselves, by overcoming computation time and memory issues that constrain classical computing.

Some of the fundamental challenges for the further development of quantum information science lie in assembling controllable and scalable quantum systems that realize not single but multiple quantum bits in quantum information processors (quantum computers, quantum simulators), and in interfacing such systems in quantum networks. The achievable degree of control relies on the ability to arbitrarily address, manipulate, and couple individual physical entities, like single atoms or single photons, which are used as information carriers. The interfacing of atoms and photons, the storage and retrieval of single photons, and the mapping of quantum states between distant entities, all constitute essential building blocks of future quantum communication networks and quantum information processors.

This ERTC aims for a critical review of the presently existing ideas, strategies and aspirations of quantum information science. The results of the ERTC will serve as background for further consideration of CAS and MPG.